1. Technical Field
The present invention relates to a head mounted display device.
2. Related Art
A head mounted display device (a head mounted display; HMD), which is a display device mounted on the head, is known. For example, the head mounted display device generates, using a liquid crystal display and a light source, image light representing an image and guides the generated image light to the eyes of a user using a projection optical system and a light guide plate to thereby cause the user to visually recognize a virtual image. As the head mounted display device, there are two types: a transmission type for enabling the user to visually recognize an outside scene in addition to the virtual image and a non-transmission type for disabling the user from visually recognizing the outside scene. As the transmission type head mounted display device, there are an optical transmission type and a video transmission type.
JP-A-2010-141548 (Patent Literature 1) discloses an image display device that classifies a plurality of frames, which form a received video signal, respectively into several types according to luminance and chroma and, when changes from a specific type of frames to the other types of frames occur a fixed number of times or more in a predetermined number of frames, deletes several frames from the predetermined number of frames to reduce the changes of the types of the frames to thereby reduce the burden on a user who visually recognizes a video.
The related art is also disclosed in “Research Report concerning the Influence of Contents on the Living Organism, March 2004, Ministry of Internal Affairs and Communications” (Non Patent Literature 1) and “Guideline by Video Method such as Animation, 2006, Japan Broadcasting Corporation, National Association of Commercial Broadcasters in Japan” (Non Patent Literature 2).
However, in the technique described in Patent Literature 1, the types of the respective plurality of frames, which form the received video signal, are identified and the changes from a specific type of frames to the other types of frames are reduced. Therefore, a certain effect is obtained concerning only a video visually recognized by the user. However, for example, it is not taken into account to cause the user to visually recognize a still image without a change in types of frames. Therefore, it is desired to reduce the burden on the user concerning the still image and the like other than the video. In the transmission type head mounted display device, a transmitted outside scene is superimposed on a received video to cause the user to visually recognize the outside scene in addition to the video. Therefore, it is desired to control, taking into account the transmitted outside scene, a virtual image that the user is caused to visually recognize. It is also desired to control, according to detected information included in the transmitted outside scene, the virtual image that the user is caused to visually recognize. Besides, in the head mounted display device in the past, improvement of convenience and the like are desired.